Oil filter



June 8, 1937. J. c. COULOMBE OIL FILTER Filed' Feb. 25, 1935 INVENTOR Q wz/u/Q Patented June 8, 1937 UNlTED STATES PATENT OFFICE Joseph C. Coulombe, Del Mar, Calif.

Application February 25, 1935, Serial No. 8,121

4 Claims.

This invention relates to oil filters for internal combustion engines, of the self-cleaning type.

One object of this invention is to provide a filter element that is automatically self-cleaning 5 by the variation of oil pressure.

Another object of this invention is to provide a filter element that is automatically self-cleaning by the vibration of the engine.

A further object of this invention is to provide a filter element that is self-cleaning by manually operated means.

A still further object of this invention is to provide an eflicient oil filter that is cheaply manufactured and readily serviced.

I obtain these objects by providing a metal coil, helically wound, supported at its outer periphery in a suitable housing.

My invention will be better understood by reference to the accompanying drawing in which:

Fig. 1 is a vertical, partly sectional, view.

Fig. 2 is an enlarged sectional view of part of the metal helical coil, forced to a conical position, showing the sliding and wiping action of the coil sections.

The helical coil l is pressed into the upper housing 2. To the central portion of coil I is secured a rod 3,,which extends through the upper housing 2 and terminates in an enlargement 4. A spring 5 is interposed between the enlargement 4 and the top of upper housing 2. A screw cap 6 is.secured to the top of upper housing 2, enclosing the enlargement 4, spring 5 and the upper section of rod 3.

The lower housing I is clamped to the upper housing 2 by means of bolts 8, a gasket 9 being interposed between the upper and lower housing to insure tightness. The lower housing forms a. settling chamber containing a drain valve Ill and an oil intake fitting ll having a tubular extension I2 terminating in cross-holes l3.

A threaded boss I4 is provided in the upper housing for-attaching an oil outlet fitting.

The operation is as follows:

-Oil is circulated through the filter by the oil pump of the internal combustion engine (not shown). Oil enters through intake fitting ll, through cross-holes l3 and directed substantially flow through the filter coil element, and out through outlet ill.

The deflection of the coil element is dependent on the oil flow through the coil, the larger the coil the greater quantity of oil may be passed parallel to the filter coil element I, to diffuse the through the coil for a given deflection. The deflection of the coil is primarily due to the pressure difierential between the inlet side and the outlet side of the coil. Taking for granted that the oil outlet I4 is much larger than the oilinlet l3, then the coil deflection will be due solely to the resistance of oil flow through the coil. For a given oil flow through the oil inlet IS, the smaller the coil the greater will be the coil deflection. If the filter coil element becomes clogged sufliciently to obstruct the oil flow (or is so designed intentionally), the filter poll element will be flexed toward the outlet side, due to the difierential pressure, and return to normal position when the engine is stopped. The filter coil element acts siinilarto a perforated diaphragm, it will move in and out due to differential pressures and the amount of movement will vary with varying pressures.

If the filter coil element should become jammed by dirt particles becoming wedged between the coils and thereby making inoperative the automatic self-cleaning movements, it may be freed by removing the cap 6 and manually operating the filter coil element by means of the rod 3 and enlargement 4.

The movement of the filter coil element is softened and limited'by the spring 5 in one-direction and limited in the other direction by upper housing 2 and cap 6. I,

For a given size, the thinner the material used in making the filter coil element the, greater number of interstices and the greater the-filter capacity. Likewise, the thinner and narrower the material, the more flexible the unit is and the more sensitive to pressure variation. The material cross-section may be rectangular, oval or round. An eflicient filter coil element may be produced from a strip of metal M wide,

thick and wound suificiently tight to allow .002"

I claim:

1. An oil filter for internal combustion engines comprising a, housing having an oil intake and an oil outlet, a sediment chamber in the lower portion of the housing, said oil intake extending above the lower portion of the sediment chamber, a filter element within said housing located between said oil intake and said oil outlet, said filter element consisting of a thin strip of resilient metallic material wound in a coil sufficiently loose to permit a wiping action between the individual loops of said coil as said coil varies from a flat coil to a conically shaped coil under variations of oil pressure, means for holding the periphery of said coil in a fixed position relative to said housing, and means for limiting the movement of the central portion of said coil so that the loops of said coil shall overlap.

2. An oil filter for internal combustion engines comprising a housing, a sediment chamber in the lower portion of the housing, an oil intake extending above the lower portion of the sedimentchamber, a filter element within said housing and secured thereto, said filter element being composed of a number of thin strips of resilient metallic material arranged side by side sufficiently loose so that there will be'a relative .edgewise sliding movement therebetween under varying oil pressure, and means for limiting the relative edgewise sliding action between said strips so that they will always overlap one another.

3. An oil filter for internal combustion engines comprising a housing having an oil intake and an oil outlet, a sediment chamber in the lower portion of the housing, said oil intake extending above the lower portion of said sediment chamber, a filter element within said housing located between said oil intake and said oil outlet, said filter element' consisting of a thin strip of resilient metallic material wound in a coil sufiiciently loose to permit a wiping action between the individual loops of said coil as said coil varies from a flat coil to a conically shaped coil under variations of oil pressure, means for confining the movement of the periphery of said portion of the housing, said oil intake extending above the lower portion of the sediment chamber, a filter element within said housing located between said oil intake and said oil outlet, said filter element consisting of a thin strip of resilient metallic material wound in a coil sufficiently loose to permit a wiping action between the individual'loops of said coil as said coil varies from a flat coil to a. conically shaped coil under variations of oil pressure, means for confining the movement of the periphery of said coil within said housing so that the central portion of said coil may move relative thereto in varying from a flat coil to a conically shaped coil, cooperating means between the central portion of said coil and said housing whereby the movement of the central portion of said coil relative to its periphery shall be limited so that the loops of said coil shall overlap one another, and said oil outlet having sufliciently large area so that there may be built up a pressure differential between the inlet and outlet sides to insure a relative wiping action movement between the loops of said coil.

JOSEPH cfcouwnma. 

